Add usb-ctrl for USB gadget control

The usb-ctrl is copied from [intel-bmc][1] that creates/destroy USB
mass-storage devices via USB gadget driver.
It supports multiple devices and could be extended with future features.

[1]: https://github.com/Intel-BMC/openbmc/blob/intel/meta-openbmc-mods/meta-common/recipes-core/fw-update/files/usb-ctrl

Signed-off-by: Lei YU <yulei.sh@bytedance.com>
Change-Id: Ie875e7e385ddacef82b7e4d20795c97c001384b3
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..796b96d
--- /dev/null
+++ b/.gitignore
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+/build